Antonio Larissa Machado, Martins Gustavo Henrique, Aragão Annelize Zambon Barbosa, Quel Natália Galdi, Zazeri Gabriel, Houry Walid A, Ramos Carlos Henrique Inacio
Institute of Chemistry, University of Campinas-UNICAMP, Campinas 13100-104, SP, Brazil.
Department of Biochemistry, University of Toronto, Toronto, ON M5G 1M1, Canada.
Plants (Basel). 2023 Aug 12;12(16):2925. doi: 10.3390/plants12162925.
The chaperone R2TP has multiple subunits that assist in the proper folding, assembly, and stabilization of various protein complexes in cells and its study can offer valuable insights into the regulation and maintenance of protein assemblies in plant systems. The 'T' component of R2TP is Tah1 in yeast, consisting of 111 residues, while its counterpart in humans is RPAP3, with 665 residues. RPAP3 acts as a co-chaperone of Hsp90 and facilitates interactions between RUVBL proteins and other complex components, enhancing the recruitment of client proteins by the R2TP complex. These facts further underscore the relevance of studying this complex in different organisms. The putative gene corresponding to the RPAP3 in Sorghum bicolor, a monocotyledon plant, was cloned, and the protein (396 residues) purified for biochemical characterization. SbRPAP3 exists as a folded monomer and has a RPAP3 domain, which is present in human RPAP3 but absent in yeast Tah1. SbRPAP3 retains its functional capabilities, including binding with RUVBLs, Hsp90, and Hsp70. By elucidating the role of RPAP3 in plant R2TP complex, we can further comprehend the molecular mechanisms underlying plant-specific protein assembly and contribute to advancements in plant biology and biotechnological applications.
伴侣蛋白R2TP有多个亚基，可协助细胞中各种蛋白质复合物正确折叠、组装和稳定，对其研究可为深入了解植物系统中蛋白质组装的调控和维持提供有价值的见解。R2TP的“T”组分在酵母中是Tah1，由111个氨基酸残基组成，而在人类中其对应物是RPAP3，有665个氨基酸残基。RPAP3作为Hsp90的共伴侣蛋白，促进RUVBL蛋白与其他复合物组分之间的相互作用，增强R2TP复合物对客户蛋白的招募。这些事实进一步凸显了在不同生物体中研究该复合物的重要性。克隆了单子叶植物双色高粱中与RPAP3对应的假定基因，并纯化了该蛋白（396个氨基酸残基）用于生化特性分析。SbRPAP3以折叠单体形式存在，具有一个RPAP3结构域，该结构域存在于人类RPAP3中，但在酵母Tah1中不存在。SbRPAP3保留了其功能，包括与RUVBLs、Hsp90和Hsp70结合。通过阐明RPAP3在植物R2TP复合物中的作用，我们可以进一步理解植物特异性蛋白质组装的分子机制，并推动植物生物学和生物技术应用的发展。
